import React from 'react';
import { useNavigate } from 'react-router-dom';
import { useTranslation } from 'react-i18next';
import { useQuery } from '@tanstack/react-query';
import { Check, Package as PackageIcon } from 'lucide-react';
import { YStack, XStack } from '@tamagui/stacks';
import { SizableText as Text } from '@tamagui/text';
import { Pressable } from '@tamagui/react-native-web-lite';
import { OnboardingShell } from '../components/OnboardingShell';
import { MobileCard, CTAButton, PillBadge } from '../components/Primitives';
import { getPackages, getTenantPackagesOverview, Package, trackOnboarding } from '../../api';
import { ADMIN_WELCOME_BASE_PATH, ADMIN_WELCOME_EVENT_PATH, ADMIN_WELCOME_SUMMARY_PATH, adminPath } from '../../constants';
import { getSelectedPackageId, setSelectedPackageId } from '../lib/onboardingSelection';
import { useAdminTheme } from '../theme';

export default function WelcomePackagesPage() {
  const navigate = useNavigate();
  const { t } = useTranslation('onboarding');
  const { muted } = useAdminTheme();
  const [selectedId, setSelectedId] = React.useState<number | null>(() => getSelectedPackageId());

  const { data: overview } = useQuery({
    queryKey: ['mobile', 'onboarding', 'packages-overview'],
    queryFn: () => getTenantPackagesOverview({ force: true }),
    staleTime: 60_000,
  });

  const { data: packages, isLoading, isError } = useQuery({
    queryKey: ['mobile', 'onboarding', 'packages-list'],
    queryFn: () => getPackages('endcustomer'),
    staleTime: 60_000,
  });

  const hasActivePackage =
    Boolean(overview?.activePackage) || Boolean(overview?.packages?.some((pkg) => pkg.active));

  React.useEffect(() => {
    if (!hasActivePackage) {
      return;
    }
    setSelectedPackageId(null);
    navigate(ADMIN_WELCOME_EVENT_PATH, { replace: true });
  }, [hasActivePackage, navigate]);

  const handleSelect = (pkg: Package) => {
    setSelectedId(pkg.id);
    setSelectedPackageId(pkg.id);
    void trackOnboarding('package_selected', { package_id: pkg.id, package_name: pkg.name });
  };

  return (
    <OnboardingShell
      eyebrow={t('packages.layout.eyebrow', 'Step 2')}
      title={t('packages.layout.title', 'Choose your package')}
      subtitle={t(
        'packages.layout.subtitle',
        'Fotospiel supports flexible pricing: single-use event slots or subscriptions covering multiple events.',
      )}
      onBack={() => navigate(ADMIN_WELCOME_BASE_PATH)}
      onSkip={() => navigate(adminPath('/mobile/billing#packages'))}
      skipLabel={t('packages.cta.billing.button', 'Open billing')}
    >
      {isLoading ? (
        <MobileCard>
          <Text fontSize="$sm" color={muted}>
            {t('packages.state.loading', 'Loading packages …')}
          </Text>
        </MobileCard>
      ) : isError ? (
        <MobileCard>
          <Text fontSize="$sm" fontWeight="700">
            {t('packages.state.errorTitle', 'Failed to load')}
          </Text>
          <Text fontSize="$sm" color={muted}>
            {t('packages.state.errorDescription', 'Please try again or contact support.')}
          </Text>
        </MobileCard>
      ) : (packages?.length ?? 0) === 0 ? (
        <MobileCard>
          <Text fontSize="$sm" fontWeight="700">
            {t('packages.state.emptyTitle', 'Catalogue is empty')}
          </Text>
          <Text fontSize="$sm" color={muted}>
            {t('packages.state.emptyDescription', 'No packages are currently available. Reach out to support to enable new offers.')}
          </Text>
        </MobileCard>
      ) : (
        <YStack space="$3">
          {packages?.map((pkg) => (
            <PackageCard
              key={pkg.id}
              pkg={pkg}
              selected={selectedId === pkg.id}
              onSelect={() => handleSelect(pkg)}
            />
          ))}
        </YStack>
      )}

      <MobileCard space="$2">
        <Text fontSize="$sm" fontWeight="800">
          {t('packages.step.title', 'Activate the right plan')}
        </Text>
        <Text fontSize="$sm" color={muted}>
          {t('packages.step.description', 'Secure capacity for your next event. Upgrade at any time – only pay for what you need.')}
        </Text>
      </MobileCard>

      <XStack space="$2">
        <CTAButton
          label={t('packages.cta.summary.button', 'Continue to summary')}
          onPress={() => navigate(ADMIN_WELCOME_SUMMARY_PATH)}
          disabled={!selectedId}
          fullWidth={false}
        />
        <CTAButton
          label={t('packages.cta.billing.button', 'Open billing')}
          tone="ghost"
          onPress={() => navigate(adminPath('/mobile/billing#packages'))}
          fullWidth={false}
        />
      </XStack>
    </OnboardingShell>
  );
}

function PackageCard({
  pkg,
  selected,
  onSelect,
}: {
  pkg: Package;
  selected: boolean;
  onSelect: () => void;
}) {
  const { t } = useTranslation('onboarding');
  const { primary, border, accentSoft, muted } = useAdminTheme();
  const badges = [
    t('packages.card.badges.photos', { count: pkg.max_photos ?? 0, defaultValue: 'Unlimited photos' } as any),
    t('packages.card.badges.guests', { count: pkg.max_guests ?? 0, defaultValue: 'Unlimited guests' } as any),
    t('packages.card.badges.days', { count: pkg.gallery_days ?? 0, defaultValue: 'Unlimited days' } as any),
  ];

  return (
    <Pressable onPress={onSelect}>
      <MobileCard borderColor={selected ? primary : border} space="$2">
        <XStack alignItems="center" justifyContent="space-between">
          <XStack alignItems="center" space="$2">
            <XStack width={36} height={36} borderRadius={12} backgroundColor={accentSoft} alignItems="center" justifyContent="center">
              <PackageIcon size={18} color={primary} />
            </XStack>
            <YStack>
              <Text fontSize="$sm" fontWeight="800">
                {pkg.name}
              </Text>
              <Text fontSize="$xs" color={muted}>
                {t('packages.card.description', 'Ready for your next event right away.')}
              </Text>
            </YStack>
          </XStack>
          <PillBadge tone={selected ? 'success' : 'muted'}>
            {selected ? t('packages.card.selected', 'Selected') : t('packages.card.select', 'Select package')}
          </PillBadge>
        </XStack>
        <XStack flexWrap="wrap" space="$2">
          {badges.map((badge) => (
            <PillBadge key={badge as any} tone="muted">
              {badge as any}
            </PillBadge>
          ))}
        </XStack>
        {selected ? (
          <XStack alignItems="center" space="$1">
            <Check size={14} color={primary} />
            <Text fontSize="$xs" color={primary} fontWeight="700">
              {t('packages.card.selected', 'Selected')}
            </Text>
          </XStack>
        ) : null}
      </MobileCard>
    </Pressable>
  );
}